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Case Studies
PVDF products pass the 'acid test', out-performing stainless
steel
ST. LOUIS, MO.-
The sulfuric acid that is used to remove rust from products at a
Missouri manufacturing facility was causing a continual problem.
The acid was corroding and eating through the stainless steel piping
that carried the liquid, requiring the costly replacement of the
piping system about every six months. The manufacturing company
sought the assistance of Corrosion Products, Inc. of St. Louis,
Mo., in coming up with a solution. What Corrosion Products recommended
was PVDF pipe, valves and fittings. "The company said they
hadn't used a lot of plastics there at the plant," said Rick
Bradbury, vice president of sales for Corrosion Products. "The
pipe would have to stand up to a lot of chemical and physical abuse."
Thus, a portion of the PVDF piping was installed in November 1997
as a test in one of the most demanding areas of the system carrying
the acid. Now, nearly six months later, the test has been judged
a complete success. "The PVDF out-performed the stainless steel
both in chemical compatibility and in its ability to withstand physical
abuse," Bradbury said. "This first portion of the project
has exceeded all expectations and the rest of the project is now
under way." A spokesman for the Missouri manufacturing firm
said PVDF piping systems are on their way to solving a vexing problem
with sulfuric acid that stainless steel just couldn't handle. "I
guess you could say that the PVDF passed the 'acid test',"
the spokesman said.
Plastic plays a major role in ensuring that water is safe and
clean
Residents of Louisville, Ky., consume 120 million gallons of fresh
water every day. Vital to human existence, the water is used for
drinking, cooking, bathing and a host of other purposes from lawn
care to washing the family car.
Plastic pipe, valves and fittings play a major role in ensuring
that this water is safe and clean for people and the environment.
Fresh water piped into the Louisville Water Co. and sewerage entering
the Metropolitan Sewer District is treated with chemicals carried
through the flow systems by plastic piping products.
Thermoplastic piping products have a very successful history at
these and other metropolitan water systems going back to the 1950s.
PVC schedule 80 products carry the chlorine, ferric chloride, ammonia,
organic polymer, calcium hydroxide, sodium hydroxide, and other
chemicals used to treat the water as it passes through the city's
fresh water and sewage treatment systems prior to its return to
the Ohio River.
At the water and sewage treatment facilities, the process used
to treat the water is similar. First, large debris - everything
from floating tree trunks to rusted car fenders - is screened out
before the water goes to settling basins.
Plastic piping products are then used to transport organic polymer,
ferric chloride or other flocculation chemicals into the water,
causing solid matter to gather together, so that it can be skimmed
off or otherwise separated from the water.
PVC is the product of choice to carry these chemicals because
of its resistance to corrosion. PVC is known to be resistant to
a broad range of chemicals, has long-term strength, and is very
cost effective.
Because CPVC has similar chemical-resistance qualities, it is sometimes
used in locations in which the environmental temperature extends
to the upper range of PVC's capability (110F - 140F). In these instances,
the increased material cost for CPVC may be justified by the comparative
reduced construction cost for less-frequent pipe supports as compared
to PVC. At the Louisville water treatment facilities, plastic piping
products range in size from 1-inch to 12-inches in diameter.
Louisville residents expect fresh, clean water when they turn on
their taps each day. At the same time, they want the Ohio River
kept clean of pollutants. Plastic products are on the job to meet
both of these important needs.
Plastic piping products to play big role in Brazil's new water
park
RIO DE JANEIRO, Brazil -
Plastic piping products had an integral part in providing fun for
thousands of visitors to the giant Wet 'n Wild water park in this
popular international city.
Millions of gallons of water are pumped and filtered through a
thermoplastic piping system, allowing kids of all ages to roar down
the Kamikaze water slide, body surf in the Surf Lagoon, and thrill
to other state-of the-art rides, pools and attractions.
Narlon Parten of Southwest Pipe and Supply Co. in Fort Worth, Texas,
the company that supplied the project, said that the water park
in Rio de Janeiro is the fourth international Wet 'n Wild project
for Southwest Pipe and Supply Co. Wet 'n Wild water parks have been
completed in the Brazilian cities of Salvador and Säo Paulo,
and in Cancun, Mexico.
The Rio project required more than 10,000 pounds of PVC/CPVC piping
components ranging in size from 1/2 inch to 12 inches. Included
were 144 12-inch Van Stone flanges and more than 200 10-inch and
12-inch fittings. In addition, metal butterfly and check valves
also were used at the new water park.
Plastic Pipe Means Clean Air
Clean air was the main objective when considering a compressed-air
piping system for Hawkins Chemical Inc.'s new chemical-blending
facility for the food and beverage industry. After considering the
various piping systems that offer "clean air," Hawkins
Chemical chose a proprietary ABS system for their expansion in Minneapolis,
MN.
PVC and CPVC cannot be used with compressed air because both can
break into sharp pieces which can be accelerated by decompressing
air. ABS has a rubber-based component which allows the pipe to split
and release the energy without breaking up. This engineered material
exceeded the design requirements of Hawkins Chemical engineers.
In addition, the smooth inside diameter and no-leak joints will
provide years of maintenance-free clean-air service.
The highly visible green pipe, valves and fittings are used in
equipment airdrops throughout the plant for operating pumps, valves,
and controls within the chemical blending process. The piping system
at Hawkins withstands temperature swings of 30° F and is pressurized
up to 140 psi.
Stainless steel piping was also considered for its clean-air properties.
The Hawkins engineers knew stainless steel would be compatible with
the various chemicals used and considered stainless steel to be
a low-maintenance product. But, they also knew the threaded connections
of stainless steel would add considerable dollars to the installation
costs, and the air leaks through those joints would add to their
energy bills each month, not to mention the high material cost of
stainless steel.
While working with Mark Madison, vice president of sales and marketing
at Indelco Plastics Corp., on the process piping and holding tanks
for this project, Hawkins Chemical was made aware of the ABS system
and its features and benefits. After careful consideration, the
choice was easy to make.
Tim Jorges, maintenance supervisor of Hawkins Chemical, and his
personnel installed more than 2,000 feet of the special plastic
piping without the need of outside contractors and engineers.
They ran a few lines to a currently empty portion of the facility
for additional expansion knowing that adding on to the system in
the future is simple and cost effective. Hawkins Chemical slashed
material and installation costs by using plastic as they continue
to enjoy a "clean air" piping system, which was easy to
install, is corrosion resistant and tough enough to handle the service
conditions.
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